Lubricating compositions, greases, and aqueous fluids are used to maintain a film of lubricant between surfaces which are moving with respect to each other. The compositions prevent contact of the moving surfaces thus preventing harmful wear to the surfaces. The compositions generally also lower the coefficient of friction. To be effective, the compositions must have sufficient antiwear, antiweld, and extreme pressure properties to prevent metal-to-metal contact under high load conditions. There is a desire to have a material or combinations of materials which provide lubricating compositions with antiwear, antiweld, extreme pressure and/or friction properties.
One problem associated with boundary lubrication occurs under high speed, shock loading conditions. Under these conditions, the lubricant is exposed to a quick heavy load which may cause metal-to-metal contact. The L-42 high speed, shock loading test measures a lubricants ability to protect under high speed, shock loading conditions.
U.S. Pat. No. 3,505,222, issued to Niebylski relates to lubricant compositions having extreme pressure wear properties. The lubricants contain a synergistic mixture of a thiosulfate compound and a lead compound. The thiosulfates include metal thiosulfates and quaternary ammonium thiosulfates. The lead compounds include lead naphthenate, lead imidazole, lead isodecyl xanthogenate, lead oleate, lead stearate, lead sulfide, and lead octyl xanthogenate.
U.S. Pat. No. 4,923,625 relates to lubricant compositions with improved extreme pressure and antiwear properties which contain a mixture of a metal thiosulfate and a metal phosphate.